<!doctype html> 
<html> 
<head> 
    <meta charset="utf-8"> 
    <title></title> 
</head>
<body>
<script type="text/javascript">
	
	var a = 'olev';//love
	//no charAt replace
	var b = a.substring(0,1);
	var l = a.substring(1,2);
	var e = a.substring(2,3);
	var v = a.substring(3,4);
	alert(l+b+v+e);
</script>
</body>
</html>